1. Field of the Invention
The present invention relates to a connection-oriented communication interface management system, and more particularly to a connection-oriented communication interface management system implemented in a network node 10 which communicates with remote nodes over a multiplexed communications medium.
2. Description of the Related Art
According to a rapid proliferation of the Internet in today""s business and research environments, the development of high-speed backbone networks taking advantage of Asynchronous Transfer Mode (ATM) technologies is of increased interest. ATM, however, does not have a direct compatibility with the classical protocols used in the Internet. To solve this issue, researchers participating in the Internet Engineering Task Force (IETF) have been investigating xe2x80x9cIP Over ATMxe2x80x9d protocols to connect the Internet Protocol (IP) layer directly to an ATM network.
Conventional IP nodes, such as a router to which a plurality of terminal stations are connected, are designed to use logical communication interfaces when transmitting IP packets to remote destinations over a physical network, including a local area network (LAN) and public switched telecommunications network (PSTN). To this end, there are two types of logical communication interfaces: network interface and point-to-point interface. In the network interface, some address resolution mechanisms have to be introduced, because it is not possible to uniquely identify the destination node from a given IP address alone. The Next Hop Resolution Protocol (NHRP) and Address Resolution Protocol (ARP) have been proposed and/or used for this purpose.
In contrast to the network interface, the point-to-point interface allows a unique ATM address and VPI/VCI to be determined from a given destination IP address, without the need of address resolution mechanisms. In conventional schemes, however, one point-to-point interface is established in association with one virtual channel in a fixed manner. That is, different point-to-point interfaces are provided for individual virtual channels, meaning that a possible failure in a virtual channel would render its associated point-to-point interface invalid.
ATM, which is a connection-oriented multiplexed communications technology, also uses a point-to-point interface established together with a virtual channel before initiating a communication session. As one of its inherent features, ATM can consolidate many signal streams into one physical channel with its multiplexing mechanism, which would potentially permit the network nodes to change the relationship between a point-to-point interface and a virtual channel as required. In spite of this advantageous capability of ATM, conventional network systems provide only a limited flexibility in the association between point-to-point interfaces and virtual channels. This means that the potential advantage of ATM has been overlooked in the conventional system design.
Taking the above into consideration, an object of the present invention is to provide a connection-oriented communication interface management system which permits a connection-oriented multiplexed communications network to fully enjoy the advantages of ATM technologies, by giving more flexibility to a link management mechanism that associates connection-oriented communication interfaces with virtual channels.
To accomplish the above object, according to the present invention, there is provided a connection-oriented communication interface management system disposed in a node which communicates with peer nodes by using multiplexed communications techniques. This system comprises a virtual channel set-up unit which establishes a virtual channel to a peer node and an interface set-up unit which establishes a connection-oriented communication interface to reach the peer node and associates the connection-oriented communication interface with the virtual channel established by the virtual channel set-up unit.